摘要:
Antimicrobial resistance is a global health security issue of widespread concern. Recent studies have unveiled the potential contribution of non-antibiotics to the emergence of antimicrobial resistance. This study investigated the effect of carbamazepine, a non-antibiotic pharmaceutical, on the fate of antibiotic resistance genes (ARGs) during anaerobic digestion. The results, as revealed by both metagenomic sequencing and absolute quantification, demonstrated that carbamazepine induced the enrichment of ARGs and increased the abundance of ARGs hosts by 1.2-2.1 times. Carbamazepine facilitated microbial aggregation and intercellular communication by upregulating functional genes associated with two-component systems, quorum sensing and type IV secretion systems, thereby increasing the frequency of ARGs conjugation. Furthermore, carbamazepine induced the acquisition of ARGs by pathogens and elevated the overall pathogenic abundance. This study revealed the mechanisms of microbial self-regulation and ARGs transmission under carbamazepine stress, highlighting the potential health risks posed by non-antibiotic pharmaceuticals during the safe disposal of sludge.
摘要:
Eucalyptus was one of the most cultivated hardwood species worldwide, with rapid growth, good wood properties and a wide range of adaptability. Eucalyptus stem undergoes primary growth (longitudinal growth) followed by secondary growth (radial growth), which produces biomass that is an important source of energy worldwide. In order to better understand the genetic regulation of secondary growth in Eucalyptus grandis, Transcriptome analyses in stem segments along a developmental gradient from the third internode to the eleventh internode of E. grandis that spanned primary to secondary growth were carried out. 5,149 genes that were differentially expressed during stem development were identified. Combining the trend analysis by the Mfuzz method and the module-trait correlation analysis by the Weighted Gene Co-expression Network Analysis method, a total of 70 differentially expressed genes (DEGs) selected from 868 DEGs with high connectivity were found to be closely correlated with secondary growth. Results revealed that the differential expression of these DEGs suggests that they may involve in the primary growth or secondary growth. AP1, YAB2 TFs and EXP genes are highly expressed in the IN3, whereas NAC, MYB TFs are likely to be important for secondary growth. These results will expand our understanding of the complex molecular and cellular events of secondary growth and provide a foundation for future studies on wood formation in Eucalyptus.
摘要:
Bacteria colonized on solid electrode developing electroactive biofilm (EAB) has been shown to promote the contaminants biodegradation. Regulating electrode potential can improve the stability of extracellular electron transfer (EET), but how the electrode potential regulating the extracellular polymer secretion and the tetracycline (TC) removal has not been fully studied. Here, EAB cultured at 0 V was used to study the degradation mechanism of TC at different electrode potentials. Results showed that −0.1 V was the optimized electrode potential for TC biodegradation compared with 0.1 V, 0 V and −0.3 V, which was 28 % higher than that without electric field. Stimulation of electric field can retain proper extracellular polymer (EPS) to relieve the poison of TC, while excessive extracellular polysaccharide (PS) at 0 V have hindered the contact between microorganisms and TC, thus limited electron transfer and reduced the TC biodegradation efficiency. Excessively negative potential (−0.3 V) will restrict the electron transfer which was not conducive to the biodegradation of organic pollutants. Microbial community analysis revealed that TC addition have refreshed the EAB structure, Dokdonella and Norank_f_Rikenellaceae replaced Geobacter as the dominant species in EAB to promote TC biodegradation. The variation of metabolic pathway was suggested that the up-regulation of pyruvate metabolism and ubiquinone synthesis at −0.1 V have promoted the TC removal. This study has provided theoretical support for the electrode potential regulating the extracellular polymer secretion and promoting the pollution bioremediation.
期刊:
Expert Systems with Applications,2024年244:121150 ISSN:0957-4174
通讯作者:
Zhang, DZ
作者机构:
[Ji, Bin; Zhou, Saiqi; Zhang, Dezhi; Zhang, DZ] Cent South Univ, Sch Traff & Transportat Engn, Changsha 410075, Hunan, Peoples R China.;[Li, Shuangyan] Cent South Univ Forestry & Technol, Coll Logist & Transportat, Changsha 410004, Hunan, Peoples R China.
通讯机构:
[Zhang, DZ ] C;Cent South Univ, Sch Traff & Transportat Engn, Changsha 410075, Hunan, Peoples R China.
关键词:
Two-echelon vehicle routing problem;Direct deliveries;Access time windows;Integer linear programming model;Adaptive large neighborhood search
摘要:
Nowadays, heavy-duty trucks are usually restricted from entering urban areas due to emission and congestion problems in most cities. So, a two-echelon distribution system becomes vastly applicable, in which satellites transfer cargo and avoid heavy-duty trucks entering urban areas. However, with the development of new energy vehicles and access policies and regulations, some environmentally friendly trucks are accessible to urban areas within specific time windows of daytime directly. In light of this, we introduce a two-echelon vehicle routing problem with direct deliveries and access time windows (2E-VRPDDATW) arising in city logistics. In this problem, customers are served by the two-echelon distribution systems within their required time windows and are allowed to be directly delivered by the first echelon vehicles within access time windows, which provides more flexible routing schemes. A novel mixed integer linear programming (MILP) model for the above problem is presented, and the corresponding adaptive large neighborhood algorithm is developed. The computational experiments are provided to verify the validity of the proposed model and the effectiveness of the algorithm. Finally, the sensitivity analysis shows some interesting findings about the number of two-echelon vehicles and the assignment of customers. Moreover, we conclude that direct deliveries are advantageous in transportation costs when the proportion of the end time of access time window to the last end time of customers is greater than 0.25.
摘要:
The anisotropic behavior of as-extruded 7003 aluminum alloy under quasi-static compression and high-speed impact was studied using samples with axes parallel to extrusion direction (ED) (0 degrees sample), at an angle of 45 degrees to ED (45 degrees sample), and perpendicular to ED (90 degrees sample). The experimental results show that the yield stress of the 0 degrees sample is the highest, while the 45 degrees sample is the lowest. Compared with other samples, the 90 degrees sample is more sensitive to the applied strain rate, which experiences a rapid failure after reaching peak stress under high-speed impact. Under quasi-static compression and high-speed impact, the 0 degrees sample exhibits nearly uniform deformation, while the 45 degrees and 90 degrees samples exhibit anisotropy behavior. Due to the occurrence of adiabatic shear, the plastic deformation anisotropy in 45 degrees and 90 degrees samples under high-speed impact is more significant compared to quasi-static compression. For the 45 degrees and 90 degrees samples, the r values, which characterize plastic deformation anisotropy, decrease from 0.77 to 0.82 under quasi-static compression to 0.46 and 0.40 under high-speed impact. In addition, adiabatic shear bands are observed in all deformed samples under highspeed impact, while only the 90 degrees sample fractures. Due to the significant difference in Schmidt factors along ED and transverse direction (TD), plastic deformation of the 90 degrees sample under high-speed impact is mainly concentrated in TD, while the deformation in ED is very small. The extremely uneven deformation leads to earlier nucleation and faster development of ASBs in TD, causing the 90 degrees sample to fracture under high-speed impact.
作者机构:
[Tian, Yunlong; Wu, Pengfei; Li, Linxin; Xu, Jingjing; Ma, Xiangqing] College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, Fujian, China;[Tian, Yunlong; Wu, Pengfei; Li, Linxin; Xu, Jingjing; Ma, Xiangqing] Chinese Fir Engineering Technology Research Center of the State Forestry and Grassland Administration, Fuzhou, Fujian, China;[Farooq, Taimoor Hassan] Bangor College, Central South University of Forestry and Technology, Changsha, Hunan, China
摘要:
BACKGROUND: The continuous establishment of Chinese fir (Cunninghamia lanceolata) plantations across multiple generations has led to the limited impact of soil phosphorus (P) on tree growth. This challenge poses a significant obstacle in maintaining the sustainable management of Chinese fir. METHODS: To investigate the effects of Arbuscular mycorrhizal fungi (AMF) on the growth and physiological characteristics of Chinese fir under different P supply treatments. We conducted an indoor pot simulation experiment in the greenhouse of the Forestry College of Fujian Agriculture and Forestry University with one-and-half-year-old seedlings of Chinese fir from March 2019 to June 2019, with the two P level treatment groups included a normal P supply treatment (1.0 mmolL(-1) KH(2)PO(4), P1) and a no P supply treatment (0 mmolL(-1) KH(2)PO(4), P0). P0 and P1 were inoculated with Funneliformis mosseae (F.m) or Rhizophagus intraradices (R.i) or not inoculated with AMF treatment. The AMF colonization rate in the root system, seedling height (SH), root collar diameter (RCD) growth, chlorophyll (Chl) photosynthetic characteristics, enzyme activities, and endogenous hormone contents of Chinese fir were estimated. RESULTS: The results showed that the colonization rate of F.m in the roots of Chinese fir seedlings was the highest at P0, up to 85.14%, which was 1.66 times that of P1. Under P0 and P1 treatment, root inoculation with either F.m or R.i promoted SH growth, the SH of R.i treatment was 1.38 times and 1.05 times that of F.m treatment, respectively. In the P1 treatment, root inoculation with either F.m or R.i inhibited RCD growth. R.i inhibited RCD growth more aggressively than F.m. In the P0 treatment, root inoculation with F.m and R.i reduced the inhibitory effect of phosphorus deficiency on RCD. At this time, there was no significant difference in RCD between F.m, R.i and CK treatments (p < 0.05). AMF inoculation increased Fm, Fv, Fv/Fm, and Fv/Fo during the chlorophyll fluorescence response in the tested Chinese fir seedlings. Under the two phosphorus supply levels, the trend of Fv and Fm of Chinese fir seedlings in different treatment groups was F.m > R.i > CK. Under P0 treatment, The values of Fv were 235.86, 221.86 and 147.71, respectively. The values of Fm were 287.57, 275.71 and 201.57, respectively. It increased the antioxidant enzyme activity and reduced the leaf's malondialdehyde (MDA) content to a certain extent. CONCLUSION: It is concluded that AMF can enhance the photosynthetic capacity of the host, regulate the distribution of endogenous hormones in plants, and promote plant growth by increasing the activity of antioxidant enzymes. When the P supply is insufficient, AMF is more helpful to plants, and R.i is more effective than F.m in alleviating P starvation stress in Chinese fir.
摘要:
<bold>Background:</bold> Chlamydia is a Gram-negative obligate intracellular bacterium that is pathogenic for humans and a large variety of veterinary animal species. However, there is no continuous monitoring of chlamydia infection data in pigs in Hunan province, southern China. Therefore, in order to evaluate the seroprevalence and identify risk factors associated with Chlamydia infection in pigs within this region, a comprehensive study was conducted. <bold>Methods:</bold> A total of 3848 serum samples were collected from pigs (from farmers and companies) between May 2017 and August 2018. The presence of specific antibodies against Chlamydia was determined through the employment of the indirect hemagglutination assay (IHA). <bold>Results:</bold> The overall seroprevalence of Chlamydia was determined to be 26.90% (1038/3848, 95% confidence interval: 25.60-28.40). By employing statistical analysis using SPSS software (p < 0.05), factors such as altitude, sampling regions, and rearing systems of pigs were identified as potential risk factors for Chlamydia infection. <bold>Conclusion:</bold> These findings elucidate a substantial prevalence of Chlamydia in pigs within the mountainous region of Hunan province, southern China, thereby highlighting a potential risk to human health. These results underscore the need for proactive measures and targeted interventions to mitigate the transmission of Chlamydia in porcine populations, safeguarding both animal welfare and public health.
摘要:
Dew-point indirect evaporative cooling (DPIEC) technology is designed and applied as a low carbon-emission and high energy-efficient air conditioning (AC) solution without employing non-environmentally friendly refrigerant and mechanical compressor for cooling in building sector. A more realistic three-dimensional (3-D) model of the DPIEC that better captures the fundamental thermodynamic of its operation is proposed. It considers the variability of air thermal properties and is employed to investigate the DPIEC's performance for three possible arrangements. The 3-D model is classified as configurations 1, 2 and 3 based on the relative flow direction between primary/secondary air and spray water. Experimental results indicate that the model can well evaluate the thermodynamic performance. Additionally, the influence of crucial factors on the performance is parametrically studied by employing three performance indexes. Comparison reveals that configuration 1 can achieve the highest effectiveness and cooling capacity. Results also show that the secondary-to-primary air ratio should be confined to around 0.3 to achieve maximum cooling capacity, and the optimal channel gap should be limited to the range from 3 to 4 mm. Comparatively, the relative flow direction between the spray water and the primary/secondary air has a greater effect on the thermodynamic performance than the spray water inlet velocity.
摘要:
Exploring the single relationship between the inversion degree of spinel and its catalytic performance is a great challenge, but has important significance for further structural design and application. A series of CoMn inverse spinels were prepared and the general formula (Co-1-x(2+) Co-x(3+)) (tet) (Mn-1(3+) Co-x(2+) Co-1-x(3+))(oct)O-4 was deduced through X-ray diffraction refinement to find a decreased inversion degree x as calcination temperature rose. Catalytic oxidation of toluene showed that higher inversion degree (S-300 with x approximate to 0.95) can reach larger conversion rate (90 % at about 250 degrees C for 400 ppm toluene) with greater reaction stability (140 h). Density Functional Theory (DFT) calculations on density of states indicated its metallic nature, and found that the strength of O-p and Transition metal-d orbitals at Fermi energy is positively correlated to the inversion degree, meaning stronger electron migration ability. Along with the adsorption calculation analysis that lattice oxygen species are proved to work dominantly (S-300 with lowest adsorption energy but highest performance), this work uncovered a theoretical insight into inverse spinel oxide, to provide the possibility of elevated oxidation ability through structural control.
期刊:
IEEE Transactions on Intelligent Transportation Systems,2024年 ISSN:1524-9050
通讯作者:
Ji, B
作者机构:
[Ji, Bin; Ji, B; Zhou, Saiqi; Zhang, Dezhi] Cent South Univ, Sch Traff & Transportat Engn, Changsha 410075, Peoples R China.;[Li, Shuangyan] Cent South Univ Forestry & Technol, Coll Logist & Transportat, Changsha 410004, Hunan, Peoples R China.
通讯机构:
[Ji, B ] C;Cent South Univ, Sch Traff & Transportat Engn, Changsha 410075, Peoples R China.
关键词:
Two-echelon capacitated vehicle routing problem;sharing satellite resources;mixed integer linear programming model;adaptive large neighborhood search
摘要:
Collaboration vehicle routing has garnered increasing attention recently because it can help enterprises reduce costs by sharing resources. This paper addresses a novel two-echelon capacitated vehicle routing problem with sharing satellite resources (2E-CVRPSSR), which arises with the development of e-commerce and the Sharing economy in city logistics. In this problem, goods are delivered within a two-echelon routing network, where satellites are used to consolidate and transfer goods between first-and second-echelon routing. Moreover, the second-echelon vehicles can depart from and return to different satellites. A mixed integer linear programming model is first presented, and an adaptive large neighborhood search algorithm with several new search operators and strategies is proposed to solve this problem. The numerical results show that the proposed algorithm can effectively solve the 2E-CVRPSSR. Moreover, an average transportation cost savings of 6.29% can be obtained by sharing satellite resources. In addition, geographic analysis indicates that the layout of the depot, satellites, and customers largely impacts the economic advantages of sharing satellite resources. Specifically, the highest economic benefits are achieved when the satellites are distributed from nearest to farthest from the depot, with customers located between nearby and distant satellites and with satellites of large enough capacity close to the depot.
作者机构:
[Feng, Xiuxia] Shanghai Lida Univ, Sch Gen Educ & Foreign languages, Shanghai 201608, Peoples R China.;[Liu, Huying] Cent South Univ Forestry & Technol, SWAN Coll, Changsha 410211, Peoples R China.;[Liu, Huying] Stamford Int Univ, Grad Sch, Bangkok 10250, Thailand.
通讯机构:
[Liu, HY ] C;Cent South Univ Forestry & Technol, SWAN Coll, Changsha 410211, Peoples R China.;Stamford Int Univ, Grad Sch, Bangkok 10250, Thailand.
摘要:
This phenomenological study explored the experiences of language learners in the digital age, specifically investigating the intersection of digital literacy, technostress, online engagement, autonomy, and academic success. Twenty participants, selected through purposive sampling, shared Chinese as their native language and were between 18 and 20 years old, with five participants being female. Employing interviews and document analysis, the study aimed to understand the subjective meanings, emotions, and perceptions associated with these phenomena. The findings revealed the multifaceted nature of technostress, the crucial role of digital literacy in shaping online engagement and autonomy, and the nuanced impact on academic success. These qualitative insights contribute to a deeper understanding of the complex relationships in the digital language learning landscape. The study has implications for educators, materials developers, syllabus designers, and policy-makers, providing practical insights to enhance language learning experiences in the digital era. Future research may further explore specific dimensions uncovered in this study to adapt educational practices to the evolving digital terrain.
摘要:
Engelmann spruce (Picea engelmannii) is one of the most economically important tree species in the western United States. The species is widely distributed in mid- to high-elevation mountains, so its vulnerability to wind and snow is of concern to foresters. Height-to-diameter (H-D) ratio is an important metric for assessing tree stability and resistance to windstorm and icing damage. But our understanding of the variation in H-D ratio of Engelmann spruce and its driving mechanism is limited. Based on inventory data of 9004 Engelmann spruce trees from 997 permanent plots, this study used the random forest algorithm, an important machine learning method, to develop the H-D ratio model of Engelmann spruce related to competition, site condition, climate, topography and other environmental variables. We used cross-validation to train and optimize H-D ratio model, and then used variable importance ranking and partial dependence plot to quantify and analyze the effects of environmental factors on H-D ratio. Further, structural equation was used to perform path analysis between the response variable and the explanatory variables. The results reveal that competition contributes the most to changes in H-D ratio, followed by site index, topography and climate variables. The H-D ratio is positively affected by competition (DBH dominance and number of neighbors), site index, and May to September precipitation, but negatively affected by elevation. The results of path analysis indicate that the effects of elevation and May to September precipitation on H-D ratio can be mediated by site index. Although we sampled across broad climatic gradients, the effects of climate on H-D ratio were not as large as expected. In conclusion, competition is the primary driver for the variation in H-D ratio of Engelmann spruce, but the influence of environmental conditions including site quality, topography and climate on tree H-D ratio cannot be ignored. When designing management treatments for Engelmann spruce forests, we need to fully consider the potential effects of stand characteristics and environmental factors on tree stability.
摘要:
Antimony pollution is well recognized to induce cancer and deformity. By polymerization technique, a carbon aerogel microsphere (Ce@SCA) modified by Ce and S with micron size, well-developed pore structure, and large specific surface area was created. Ce@SCA exhibited the advantages of efficient selectivity and high adsorption capacity for Sb(III) in water. The highest adsorption capacity derived using the Sips isothermal model was 345.18 mg.g(-1), and the Sb (III) adsorption process was thermodynamically estimated as spontaneous, exothermic, and entropy-decreasing chemisorption. Meanwhile, Ce@SCA can convert highly toxic Sb(III) into Sb (V), which is suitable for the remediation of antimony-contaminated water bodies. X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) were analyzed to elucidate the adsorption mechanism and to propose optimized adsorption configurations. A considerable number of -OH and -SH on the surface may increase the binding site of Sb, and the creation of S-Sb, O-Sb, and Ce-O-Sb covalent bonds was the key to Sb adsorption. This research provides a simple method for preparing cerium oxide-loaded and sulfur-doped carbon aerogel (Ce@SCA) with mild conditions and no hazardous waste, which also has superior adsorption properties for Sb (III) and high reusability.
关键词:
the three-terminal ballistic junction;the alpha-T-3 lattie;the anisotropic transport
摘要:
The three-terminal ballistic junction (TBJ) has promising applications in nanoelectronics. We investigate the transport properties of aα-T(3)-based TBJ, where two typical configurations are considered, i.e. the A- and Z-TBJ. It is found that both A- and Z-TBJ exhibit transmission anisotropy, and the transmission of the A-TBJ has stronger anisotropy than that of the Z-TBJ. The amplitude of the rectification coefficient is smaller than that of phosphorene TBJ, but larger than that of graphene TBJ. When the symmetrical input is applied, the output voltage curve exhibits symmetric behavior. While in the case of asymmetric input, the symmetric behavior is broken, and the maximum value of the output voltage can reach a positive value. Interestingly, the voltage output shows a dramatic nonlinear response which may be useful for the voltage diode application with a push-pull input voltage. In addition, the heat fluxes of the asymmetric input are much smaller than those of the symmetric input. The maximum value of the heat flux under the symmetric input exceeds twice of that under the asymmetric input. Our results are useful to design nanoelectronic devices based onα-T(3)TBJ.
摘要:
Exposure to organic ultraviolet (UV) filters has raised concerns due to their potential adverse effects on environments. However, their toxic mechanisms on plants remain elusive. In this study, using integrative physiological and transcriptomic approaches we investigated the physiological and molecular responses to three representative UV filters, namely oxybenzone (OBZ), avobenzone (AVB), and octinoxate (OMC), in an agricultural model plant tobacco. The exposure to UV filters disrupts the functionality of photosystem reaction centers and the light-harvesting apparatus. Concurrently, UV filters exert a suppressive effect on the expression of genes encoding Rubisco and Calvin-Benson cycle enzymes, resulting in a decreased efficiency of the Calvin-Benson cycle and consequently hampering the process of photosynthesis. Exposure to UV filters leads to significant generation of reactive oxygen species within tobacco leaves and downregulation of oxidoreductase activities. Moreover, UV filters promote abscisic acid (ABA) accumulation by inducing the expression of ABA biosynthesis genes whereas repress indole-3-acetic acid (IAA) biosynthesis gene expression, which induce leaf yellowing and slow plant growth. In summary, the organic UV filters exert toxic effects on tobacco growth by inhibiting chlorophyll synthesis, photosynthesis, and the Calvin-Benson cycle, while generating excessive reactive oxygen species. This study sheds light on the toxic and tolerance mechanisms of UV filters in agricultural crops.